Short-circuiting device for electric motors.



G. A. SGHNUR.

SHORT CIRGUITING DEVICE FOR ELECTRIC MOTORS.

APPLICATION FILED MAY 9, 1908..

922,521. Patented May 25, 1909.

Fig.1 18

UNITED sTATEs PATENT OFFICE.

CHARLESA. SCHNUR, OF ST. LOUIS COUNTY, MISSOURI, ASSIGNOR TO WAGNER ELECTRIC & MANUF ACTURING COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

snoa'r-cmcurrme DEVICE FOR meme morons.

Specification of Letters Patent.

Patented May 25, 1909.

. Application filed May 9, 1908. Serial No. 481,912.

To all whom it may concern:

Be it known that I, CHARLns A. SoHNUR, a citizen of the United States,'residing in St. Louis county, in the State of Missouri, have invented a certain new and useful Short-Circuiting Device for Electric Motors, of which the following is such a full, clear, and exact description as will enable any one skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to a short circuiting device for electric motors, and more particularly to that class of short circuiting devices which consists of an annular member composed of lamina of copper or other good conducting material, and adapted to be reciprocated laterally to connect the individual members of a commutator or similar structure. In the present application I have shown an automatic device for securingthe lateral reciprocation of the annular member, similar to that shown in the patent to J. H. Blair, No. 7 42,280 of October 27, 1903. I do not wish, however, to limit myself to such a device, as the annular member may be reciprocated by any suitable device either automatic or-manually operated. In short circuiting devices of this class which have heretofore been used, the individual laminae of the annular member have been held together by means of a wire passed through holes formed in one end of each lamina. This wire necessarily possesses considerable stiffness with the result that the annular member was difiicult to place in position or remove from the device and that the bending of the wire often caused part of the laminae to be held out of contact with the commutator bars, thus interfering with the proper operation of the device. Y

The object of the present inventionis to provide means for retaining the laminae in position which will overcome the above obections.

In the accompanying drawings which illustrate one form of short circuiting device made in accordance with myinvention, Figure 1 is a longitudinal central section; Fig. 2.

short circuiting laminae the end retaining band or ribbon being shown, and Fig. 4 is a view similar to 3 but showing the retainmg band or ribbon in section. I

Like marksof reference refer to similar insulated from the casing 6 by means of an insulating ring 9 and are secured in position by means of a beveled ring 10 and set screws 11.

12 is a continuous contacting ring set into the inner face of the cu shaped casing 6 and adapted to be electricall bars or segments 7, as will be hereinafter more fully described.

' 15 is an annular member surrounding the shaft 5. The inner face of the member 15 is beveled, as shown at 16 Fig. 1, and the cupsha ed casing 6 is provided with an opposite y inclined face 17. Between these two inclined faces are arranged wedge-shaped weights 18 which are adapted to be moved outwardly by centrifugal force so as to reciprocate the annular member15. The member 15 is normally held in the position shown in Fig. 1 by means of a coil spring 19, bearing at one end against the annular member 15 and at the other against a collar 20 on the shaft 5. Formed in the periphery of the annular member 15 is a groove 22 in which is placed the annular short circuiting ring now to be described.

The short circuiting ring which is placed in the groove 22 consists of a large number of 70 y connected with the laminae 23 of copper or other good contacting material. Each of the laminae 23 is provided with a pair of projecting contacts 24, one of which is adapted to bear against one of the segments 7 of the commutator and the other upon the contacting ring 12 when the short circuiting ring is moved into operative position. In each of the laminae 23 is formed a slot 25 adapted to receive a band or Fig. 4. The band 26 is made of slightly greater length than the combinedthickness of the various laminae 23 so as to project somewhat at the ends, as shown at 29, Fig. 2. The ends of the band 26 are slit and bent over portions 30 are thus formed which serve as retaining means short circuiting ring.

In order to assemble the-parts it is merely necessary to withdraw the annular member 15 from the cup-shaped casing 6 and apply the ring to the groove 22, no additional retaining means being required. Owing to the great flexibility of the band 26, and to the play allowed between the band-and the laminae 23 the laminae at all times make perfect contact with the contacting ring 12 and with the various segments 7 of the commutator.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a reciprocating member, short circuiting laminae carried by said member for electrically connecting said contacts, and a flexible metallic ribbon connecting said laminae.

2. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a reciprocating member, short circuiting laminae carried by said member for electrically connecting said contacts, each of said lamina being provided with a longitudinal 'slot and a flexible metallic ribbon extending through said slots.

3. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a reciprocating member, short circuiting laminae carried by said member for electrically connecting said contacts, each of said laminae being provided with a longitudinal slot and a flexible ribbon extending through said slots, said ribbon be- -for the laminae of theing of less thickness than the width of said slots;

4. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a. r'eciprocatin memher, short circuiting laminae carried. y said member for electrically connecting said con tacts, and a flexible metallic ribbon connecting said laminae, said ribbon being provided with retaining means for said laminae.

5. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a reciprocating member, short circuiting laminae carried by said member for electrically connecting said contacts, and a flexible metallic ribbon connecting said laminae, said ribbon having bent ends laminae.

6. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts of a reciprocating member, shortcircuiting laminae carried by said member for electrically connecting said contacts, and a flexible metallic ribbon connecting said laminae the length of said ribbon being greater than the combined thickness of said laminae.

7. In a short circuiting device for electric motors, the combination with a plurality of insulated contacts, of a reciprocating member, short circuiting laminae carried by said member for electrically connecting said contacts, and a flexible connector engaging with but having movement relative to all of said laminae, whereby said laminae have uniform freedom of movement.

In testimony whereof I have hereunto set my hand and afiixed my seal in the presence of the two subscribing witnesses.

CHAS. A. SCHNUR. [L., s.]

Witnesses:

L. GUTMANN, B. M. SOHLIOHTING.

forming retaining means for said 

